I’m trying to validate promo code, address validation, and 3D Secure steps without shunting testers into a full sandbox store — thinking Figma → ProtoPie with Stripe test mode and Google Places for autocomplete, targeting sub-300ms field feedback. If you’ve built a similar setup, what tool chain kept the flow truly seamless for users while staying fast to iterate?
I’ve had good results wiring ProtoPie to a Vercel Edge Function that proxies Stripe test mode (Coupons + SetupIntents for 3DS) and Google Places, with a small KV cache so lookups stay under your “sub-300ms field feedback.” Would you be open to that proxy approach? Debounce inputs at about 150–200 ms and pre-warm the cache on screen load to avoid Places spikes, and it keeps the prototype feeling like butter instead of molasses.
To hit your sub-300ms, I pushed promo/Places/3DS to Cloudflare Workers and did local-first checks (regex + blocklist) so obvious promo typos fail instantly; ProtoPie just flips state when the worker returns requires_action for Stripe test cards. Caveat: Places latency can be jittery — — so use an AutocompleteSessionToken and restrict components=country; for prototypes, swapping to Nominatim (https://nominatim.org) kept autocomplete cheap and fast. Would you be okay trading Places biasing for speed during the Figma → ProtoPie phase?
I used a service worker (MSW) to intercept ProtoPie’s fetches and return recorded fixtures for promo validation, Google Places, and a fake “3D Secure” step with a tiny 80–120 ms jitter so it feels real without a full sandbox… Small caveat: ProtoPie’s desktop player won’t register the SW, so I load the prototype in a tiny web shell (Vite/localhost) and let MSW handle it; https://mswjs.io was the quickest way to wire it.